This invention relates to an arrangement for guiding lubricating oil in an internal-combustion engine comprising a basin which is arranged between an engine crankshaft drive and an oil sump and has at least one drain opening, and an intermediate shaft which rotates in parallel to the crankshaft and is surrounded at least partially by two struts projecting away from the basin.
From German Patent Document DE-42 04 522 C1, an arrangement in an internal-combustion engine is known which has a basin for letting off lubricating oil which covers the crankshaft drive in the direction of the oil sump. Approximately in the center below the crankshaft, the basin which extends partially along the violin-shaped connecting rod contour has an oil drain opening which acts as an oil deflector. This oil drain opening leads into a damping chamber for the gas pulses caused by the piston movement, this damping chamber comprising another drain opening which is arranged below the oil drain opening and is laterally offset with respect to the oil drain opening. The lubricating oil which is thrown off the crankshaft drive flows through this additional drain opening into the oil sump. A differential shaft may rotate in this damping chamber which is enclosed at least partially by two struts projecting away from the basin. It is disadvantageous in this case that the oil is foamed as a result of the contact with the rotating differential shaft and arrives in the oil sump in this condition.
It is an object of the invention to develop an arrangement of this type for guiding lubricating oil in an internal-combustion engine arranged between the crankshaft drive and the oil sump in such a manner that the lubricating oil released by the crankshaft drive reaches the oil tank in a largely unfoamed manner.
This object is achieved by the present invention by providing an arrangement for guiding oil in an internal-combustion engine comprising a basin which is arranged between an engine crankshaft drive and an oil sump and has at least one drain opening, and an intermediate shaft which rotates in parallel to the crankshaft and is surrounded at least partially by two struts projecting away from the basin, wherein the struts form, together with the basin, a profile which receives the intermediate shaft and which is closed with respect to the crankshaft drive.
When, in the case of an internal-combustion engine of the above-mentioned type, the projecting struts of the basin form a profile which accommodates the intermediate shaft and is closed with respect to the crankshaft drive, the intermediate shaft is shut off with respect to the entering of lubricating oil of the crankshaft drive. This lubricating oil therefore reaches the oil sump while bypassing the rotating intermediate shaft and is not foamed by the rotation.
In an advantageous development, the bottom of the basin is provided in the area of the violin-shaped connecting rod contour with curved segments which follow them and which extend, by means of the curvature, closely adjacent to this contour and therefore leave only a small gap in which oil can be mixed with air. An arrangement of two drain openings which are situated in series with respect to one another with respect to the rotating direction of the crankshaft and behind the profile ensures a reliable discharge of the lubricating oil.
The amount of oil taken from the crankshaft drive and therefore not rotating with it can be increased if roof-type shaped-out areas are arranged behind the drain openings which point in the direction of the crankshaft, are provided with scraper lips and extend directly to the violin-shaped connecting rod contour. These may bound drain ducts which contain the drain openings and guide the taken-up lubricating oil into the oil sump.
In order to provide a further improvement by also taking up the lubricating oil thrown off the counterweights arranged adjacent to the connecting rods on the crankshaft, at least adjacent to one shaped-out area, a scraper may be arranged which extends directly to the counterweight contour.
For the complete shutting-off of the intermediate shaft, the ends of the struts which are situated at a distance from the bottom of the basin, provided for example with elastic seals, may rest against wall sections of the internal-combustion engine in such a manner that they form, together with the profile, a closed volume which extends along the intermediate shaft and accommodates it. These wall sections may be lateral walls of a crankcase which extend downward beyond the crankshaft or walls of an oil tank which is flanged to the crankcase and is constructed as an oil sump. In both cases, one wall section may have an outlet opening for lubricating oil. The oil can therefore be drained which has collected in the shaft formed between one strut and the drain ducts as well as this wall section In the former case, when there is dry sump lubrication, the take-in point of the oil pump which delivers the oil into an oil receptacle constructed as a tank may be situated in this outlet opening.
A surrounding flange of the bottom which is situated on the outside may be situated in a horizontal plane arranged between the crankshaft and the intermediate shaft, the flange, which is also provided with elastic seals, being supported on the wall sections. These seals may be placed, for example, as a sealing ring which has a circular cross-section, in corresponding grooves of the flange or of the struts.
In another embodiment, they may be provided with a sealing lip which extends in a curved manner when resting against the corresponding wall section. By means of the sealing lips, positional tolerances of the bottom or of the struts with respect to the wall sections can easily be compensated. An appropriately selected direction of the curvature of the sealing lips provides that, on the one hand, no oil can emerge from the shaft at points which are not provided for this purpose; and, on the other hand, a tunnel which is arranged on the opposite side of the intermediate shaft is secured against an admission of oil from the crankshaft drive, and oil which may be situated in it can flow off in a groove of the volume receiving the intermediate shaft.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.